<!DOCTYPE html>
<meta charset="utf-8">
<link rel="author" title="Ting-Yu Lin" href="mailto:tlin@mozilla.com">
<link rel="author" title="Mozilla" href="https://www.mozilla.org">
<link rel="help" href="https://drafts.csswg.org/css-position-3/#stickypos-insets">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1377072">
<link rel="match" href="../../reference/ref-filled-green-100px-square.xht">
<meta name="assert" content="This test verifies that the sticky flex item reserves its in-flow space in the scroll container's overflow area.">

<style>
#scroller {
  overflow: hidden;
  inline-size: 100px;
  block-size: 100px;
  background-color: green;
}

#flex {
  display: flex;
  flex-direction: column;

  /* Use a small block-size so that the flex items overflow the flex container.
     It's necessary to trigger the bug. */
  block-size: 10px;
}

#non-sticky {
  flex: 0 0 80px;
  background-color: red;
}

#sticky {
  position: sticky;
  flex: 0 0 100px;
  bottom: 0;
}
</style>

<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
<div id="scroller">
  <div id="flex">
    <div id="non-sticky"></div>
    <div id="sticky"></div>
  </div>
</div>

<script>
// Scroll the scroll container down to the bottom.
document.getElementById("scroller").scrollTop="1000";
</script>
